xref: /openbmc/linux/drivers/mmc/host/renesas_sdhi_sys_dmac.c (revision 5ef12cb4a3a78ffb331c03a795a15eea4ae35155)
1 /*
2  * DMA support use of SYS DMAC with SDHI SD/SDIO controller
3  *
4  * Copyright (C) 2016-17 Renesas Electronics Corporation
5  * Copyright (C) 2016-17 Sang Engineering, Wolfram Sang
6  * Copyright (C) 2017 Horms Solutions, Simon Horman
7  * Copyright (C) 2010-2011 Guennadi Liakhovetski
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13 
14 #include <linux/device.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/dmaengine.h>
17 #include <linux/mfd/tmio.h>
18 #include <linux/mmc/host.h>
19 #include <linux/mod_devicetable.h>
20 #include <linux/module.h>
21 #include <linux/of_device.h>
22 #include <linux/pagemap.h>
23 #include <linux/scatterlist.h>
24 #include <linux/sys_soc.h>
25 
26 #include "renesas_sdhi.h"
27 #include "tmio_mmc.h"
28 
29 #define TMIO_MMC_MIN_DMA_LEN 8
30 
31 static const struct renesas_sdhi_of_data of_default_cfg = {
32 	.tmio_flags = TMIO_MMC_HAS_IDLE_WAIT,
33 };
34 
35 static const struct renesas_sdhi_of_data of_rz_compatible = {
36 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_32BIT_DATA_PORT |
37 			  TMIO_MMC_HAVE_CBSY,
38 	.tmio_ocr_mask	= MMC_VDD_32_33,
39 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ,
40 };
41 
42 static const struct renesas_sdhi_of_data of_rcar_gen1_compatible = {
43 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL,
44 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ,
45 };
46 
47 /* Definitions for sampling clocks */
48 static struct renesas_sdhi_scc rcar_gen2_scc_taps[] = {
49 	{
50 		.clk_rate = 156000000,
51 		.tap = 0x00000703,
52 	},
53 	{
54 		.clk_rate = 0,
55 		.tap = 0x00000300,
56 	},
57 };
58 
59 static const struct renesas_sdhi_of_data of_rcar_gen2_compatible = {
60 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL |
61 			  TMIO_MMC_HAVE_CBSY | TMIO_MMC_MIN_RCAR2,
62 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
63 			  MMC_CAP_CMD23,
64 	.dma_buswidth	= DMA_SLAVE_BUSWIDTH_4_BYTES,
65 	.dma_rx_offset	= 0x2000,
66 	.scc_offset	= 0x0300,
67 	.taps		= rcar_gen2_scc_taps,
68 	.taps_num	= ARRAY_SIZE(rcar_gen2_scc_taps),
69 };
70 
71 /* Definitions for sampling clocks */
72 static struct renesas_sdhi_scc rcar_gen3_scc_taps[] = {
73 	{
74 		.clk_rate = 0,
75 		.tap = 0x00000300,
76 	},
77 };
78 
79 static const struct renesas_sdhi_of_data of_rcar_gen3_compatible = {
80 	.tmio_flags	= TMIO_MMC_HAS_IDLE_WAIT | TMIO_MMC_CLK_ACTUAL |
81 			  TMIO_MMC_HAVE_CBSY | TMIO_MMC_MIN_RCAR2,
82 	.capabilities	= MMC_CAP_SD_HIGHSPEED | MMC_CAP_SDIO_IRQ |
83 			  MMC_CAP_CMD23,
84 	.bus_shift	= 2,
85 	.scc_offset	= 0x1000,
86 	.taps		= rcar_gen3_scc_taps,
87 	.taps_num	= ARRAY_SIZE(rcar_gen3_scc_taps),
88 };
89 
90 static const struct of_device_id renesas_sdhi_sys_dmac_of_match[] = {
91 	{ .compatible = "renesas,sdhi-sh73a0", .data = &of_default_cfg, },
92 	{ .compatible = "renesas,sdhi-r8a73a4", .data = &of_default_cfg, },
93 	{ .compatible = "renesas,sdhi-r8a7740", .data = &of_default_cfg, },
94 	{ .compatible = "renesas,sdhi-r7s72100", .data = &of_rz_compatible, },
95 	{ .compatible = "renesas,sdhi-r8a7778", .data = &of_rcar_gen1_compatible, },
96 	{ .compatible = "renesas,sdhi-r8a7779", .data = &of_rcar_gen1_compatible, },
97 	{ .compatible = "renesas,sdhi-r8a7743", .data = &of_rcar_gen2_compatible, },
98 	{ .compatible = "renesas,sdhi-r8a7745", .data = &of_rcar_gen2_compatible, },
99 	{ .compatible = "renesas,sdhi-r8a7790", .data = &of_rcar_gen2_compatible, },
100 	{ .compatible = "renesas,sdhi-r8a7791", .data = &of_rcar_gen2_compatible, },
101 	{ .compatible = "renesas,sdhi-r8a7792", .data = &of_rcar_gen2_compatible, },
102 	{ .compatible = "renesas,sdhi-r8a7793", .data = &of_rcar_gen2_compatible, },
103 	{ .compatible = "renesas,sdhi-r8a7794", .data = &of_rcar_gen2_compatible, },
104 	{ .compatible = "renesas,sdhi-r8a7795", .data = &of_rcar_gen3_compatible, },
105 	{ .compatible = "renesas,sdhi-r8a7796", .data = &of_rcar_gen3_compatible, },
106 	{ .compatible = "renesas,rcar-gen1-sdhi", .data = &of_rcar_gen1_compatible, },
107 	{ .compatible = "renesas,rcar-gen2-sdhi", .data = &of_rcar_gen2_compatible, },
108 	{ .compatible = "renesas,rcar-gen3-sdhi", .data = &of_rcar_gen3_compatible, },
109 	{ .compatible = "renesas,sdhi-shmobile" },
110 	{},
111 };
112 MODULE_DEVICE_TABLE(of, renesas_sdhi_sys_dmac_of_match);
113 
114 static void renesas_sdhi_sys_dmac_enable_dma(struct tmio_mmc_host *host,
115 					     bool enable)
116 {
117 	struct renesas_sdhi *priv = host_to_priv(host);
118 
119 	if (!host->chan_tx || !host->chan_rx)
120 		return;
121 
122 	if (priv->dma_priv.enable)
123 		priv->dma_priv.enable(host, enable);
124 }
125 
126 static void renesas_sdhi_sys_dmac_abort_dma(struct tmio_mmc_host *host)
127 {
128 	renesas_sdhi_sys_dmac_enable_dma(host, false);
129 
130 	if (host->chan_rx)
131 		dmaengine_terminate_all(host->chan_rx);
132 	if (host->chan_tx)
133 		dmaengine_terminate_all(host->chan_tx);
134 
135 	renesas_sdhi_sys_dmac_enable_dma(host, true);
136 }
137 
138 static void renesas_sdhi_sys_dmac_dataend_dma(struct tmio_mmc_host *host)
139 {
140 	struct renesas_sdhi *priv = host_to_priv(host);
141 
142 	complete(&priv->dma_priv.dma_dataend);
143 }
144 
145 static void renesas_sdhi_sys_dmac_dma_callback(void *arg)
146 {
147 	struct tmio_mmc_host *host = arg;
148 	struct renesas_sdhi *priv = host_to_priv(host);
149 
150 	spin_lock_irq(&host->lock);
151 
152 	if (!host->data)
153 		goto out;
154 
155 	if (host->data->flags & MMC_DATA_READ)
156 		dma_unmap_sg(host->chan_rx->device->dev,
157 			     host->sg_ptr, host->sg_len,
158 			     DMA_FROM_DEVICE);
159 	else
160 		dma_unmap_sg(host->chan_tx->device->dev,
161 			     host->sg_ptr, host->sg_len,
162 			     DMA_TO_DEVICE);
163 
164 	spin_unlock_irq(&host->lock);
165 
166 	wait_for_completion(&priv->dma_priv.dma_dataend);
167 
168 	spin_lock_irq(&host->lock);
169 	tmio_mmc_do_data_irq(host);
170 out:
171 	spin_unlock_irq(&host->lock);
172 }
173 
174 static void renesas_sdhi_sys_dmac_start_dma_rx(struct tmio_mmc_host *host)
175 {
176 	struct renesas_sdhi *priv = host_to_priv(host);
177 	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
178 	struct dma_async_tx_descriptor *desc = NULL;
179 	struct dma_chan *chan = host->chan_rx;
180 	dma_cookie_t cookie;
181 	int ret, i;
182 	bool aligned = true, multiple = true;
183 	unsigned int align = (1 << host->pdata->alignment_shift) - 1;
184 
185 	for_each_sg(sg, sg_tmp, host->sg_len, i) {
186 		if (sg_tmp->offset & align)
187 			aligned = false;
188 		if (sg_tmp->length & align) {
189 			multiple = false;
190 			break;
191 		}
192 	}
193 
194 	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_SIZE ||
195 			  (align & PAGE_MASK))) || !multiple) {
196 		ret = -EINVAL;
197 		goto pio;
198 	}
199 
200 	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
201 		host->force_pio = true;
202 		return;
203 	}
204 
205 	/* The only sg element can be unaligned, use our bounce buffer then */
206 	if (!aligned) {
207 		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
208 		host->sg_ptr = &host->bounce_sg;
209 		sg = host->sg_ptr;
210 	}
211 
212 	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_FROM_DEVICE);
213 	if (ret > 0)
214 		desc = dmaengine_prep_slave_sg(chan, sg, ret, DMA_DEV_TO_MEM,
215 					       DMA_CTRL_ACK);
216 
217 	if (desc) {
218 		reinit_completion(&priv->dma_priv.dma_dataend);
219 		desc->callback = renesas_sdhi_sys_dmac_dma_callback;
220 		desc->callback_param = host;
221 
222 		cookie = dmaengine_submit(desc);
223 		if (cookie < 0) {
224 			desc = NULL;
225 			ret = cookie;
226 		}
227 	}
228 pio:
229 	if (!desc) {
230 		/* DMA failed, fall back to PIO */
231 		renesas_sdhi_sys_dmac_enable_dma(host, false);
232 		if (ret >= 0)
233 			ret = -EIO;
234 		host->chan_rx = NULL;
235 		dma_release_channel(chan);
236 		/* Free the Tx channel too */
237 		chan = host->chan_tx;
238 		if (chan) {
239 			host->chan_tx = NULL;
240 			dma_release_channel(chan);
241 		}
242 		dev_warn(&host->pdev->dev,
243 			 "DMA failed: %d, falling back to PIO\n", ret);
244 	}
245 }
246 
247 static void renesas_sdhi_sys_dmac_start_dma_tx(struct tmio_mmc_host *host)
248 {
249 	struct renesas_sdhi *priv = host_to_priv(host);
250 	struct scatterlist *sg = host->sg_ptr, *sg_tmp;
251 	struct dma_async_tx_descriptor *desc = NULL;
252 	struct dma_chan *chan = host->chan_tx;
253 	dma_cookie_t cookie;
254 	int ret, i;
255 	bool aligned = true, multiple = true;
256 	unsigned int align = (1 << host->pdata->alignment_shift) - 1;
257 
258 	for_each_sg(sg, sg_tmp, host->sg_len, i) {
259 		if (sg_tmp->offset & align)
260 			aligned = false;
261 		if (sg_tmp->length & align) {
262 			multiple = false;
263 			break;
264 		}
265 	}
266 
267 	if ((!aligned && (host->sg_len > 1 || sg->length > PAGE_SIZE ||
268 			  (align & PAGE_MASK))) || !multiple) {
269 		ret = -EINVAL;
270 		goto pio;
271 	}
272 
273 	if (sg->length < TMIO_MMC_MIN_DMA_LEN) {
274 		host->force_pio = true;
275 		return;
276 	}
277 
278 	/* The only sg element can be unaligned, use our bounce buffer then */
279 	if (!aligned) {
280 		unsigned long flags;
281 		void *sg_vaddr = tmio_mmc_kmap_atomic(sg, &flags);
282 
283 		sg_init_one(&host->bounce_sg, host->bounce_buf, sg->length);
284 		memcpy(host->bounce_buf, sg_vaddr, host->bounce_sg.length);
285 		tmio_mmc_kunmap_atomic(sg, &flags, sg_vaddr);
286 		host->sg_ptr = &host->bounce_sg;
287 		sg = host->sg_ptr;
288 	}
289 
290 	ret = dma_map_sg(chan->device->dev, sg, host->sg_len, DMA_TO_DEVICE);
291 	if (ret > 0)
292 		desc = dmaengine_prep_slave_sg(chan, sg, ret, DMA_MEM_TO_DEV,
293 					       DMA_CTRL_ACK);
294 
295 	if (desc) {
296 		reinit_completion(&priv->dma_priv.dma_dataend);
297 		desc->callback = renesas_sdhi_sys_dmac_dma_callback;
298 		desc->callback_param = host;
299 
300 		cookie = dmaengine_submit(desc);
301 		if (cookie < 0) {
302 			desc = NULL;
303 			ret = cookie;
304 		}
305 	}
306 pio:
307 	if (!desc) {
308 		/* DMA failed, fall back to PIO */
309 		renesas_sdhi_sys_dmac_enable_dma(host, false);
310 		if (ret >= 0)
311 			ret = -EIO;
312 		host->chan_tx = NULL;
313 		dma_release_channel(chan);
314 		/* Free the Rx channel too */
315 		chan = host->chan_rx;
316 		if (chan) {
317 			host->chan_rx = NULL;
318 			dma_release_channel(chan);
319 		}
320 		dev_warn(&host->pdev->dev,
321 			 "DMA failed: %d, falling back to PIO\n", ret);
322 	}
323 }
324 
325 static void renesas_sdhi_sys_dmac_start_dma(struct tmio_mmc_host *host,
326 					    struct mmc_data *data)
327 {
328 	if (data->flags & MMC_DATA_READ) {
329 		if (host->chan_rx)
330 			renesas_sdhi_sys_dmac_start_dma_rx(host);
331 	} else {
332 		if (host->chan_tx)
333 			renesas_sdhi_sys_dmac_start_dma_tx(host);
334 	}
335 }
336 
337 static void renesas_sdhi_sys_dmac_issue_tasklet_fn(unsigned long priv)
338 {
339 	struct tmio_mmc_host *host = (struct tmio_mmc_host *)priv;
340 	struct dma_chan *chan = NULL;
341 
342 	spin_lock_irq(&host->lock);
343 
344 	if (host->data) {
345 		if (host->data->flags & MMC_DATA_READ)
346 			chan = host->chan_rx;
347 		else
348 			chan = host->chan_tx;
349 	}
350 
351 	spin_unlock_irq(&host->lock);
352 
353 	tmio_mmc_enable_mmc_irqs(host, TMIO_STAT_DATAEND);
354 
355 	if (chan)
356 		dma_async_issue_pending(chan);
357 }
358 
359 static void renesas_sdhi_sys_dmac_request_dma(struct tmio_mmc_host *host,
360 					      struct tmio_mmc_data *pdata)
361 {
362 	struct renesas_sdhi *priv = host_to_priv(host);
363 
364 	/* We can only either use DMA for both Tx and Rx or not use it at all */
365 	if (!host->pdev->dev.of_node &&
366 	    (!pdata->chan_priv_tx || !pdata->chan_priv_rx))
367 		return;
368 
369 	if (!host->chan_tx && !host->chan_rx) {
370 		struct resource *res = platform_get_resource(host->pdev,
371 							     IORESOURCE_MEM, 0);
372 		struct dma_slave_config cfg = {};
373 		dma_cap_mask_t mask;
374 		int ret;
375 
376 		if (!res)
377 			return;
378 
379 		dma_cap_zero(mask);
380 		dma_cap_set(DMA_SLAVE, mask);
381 
382 		host->chan_tx = dma_request_slave_channel_compat(mask,
383 					priv->dma_priv.filter, pdata->chan_priv_tx,
384 					&host->pdev->dev, "tx");
385 		dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__,
386 			host->chan_tx);
387 
388 		if (!host->chan_tx)
389 			return;
390 
391 		cfg.direction = DMA_MEM_TO_DEV;
392 		cfg.dst_addr = res->start +
393 			(CTL_SD_DATA_PORT << host->bus_shift);
394 		cfg.dst_addr_width = priv->dma_priv.dma_buswidth;
395 		if (!cfg.dst_addr_width)
396 			cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
397 		cfg.src_addr = 0;
398 		ret = dmaengine_slave_config(host->chan_tx, &cfg);
399 		if (ret < 0)
400 			goto ecfgtx;
401 
402 		host->chan_rx = dma_request_slave_channel_compat(mask,
403 					priv->dma_priv.filter, pdata->chan_priv_rx,
404 					&host->pdev->dev, "rx");
405 		dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__,
406 			host->chan_rx);
407 
408 		if (!host->chan_rx)
409 			goto ereqrx;
410 
411 		cfg.direction = DMA_DEV_TO_MEM;
412 		cfg.src_addr = cfg.dst_addr + host->pdata->dma_rx_offset;
413 		cfg.src_addr_width = priv->dma_priv.dma_buswidth;
414 		if (!cfg.src_addr_width)
415 			cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
416 		cfg.dst_addr = 0;
417 		ret = dmaengine_slave_config(host->chan_rx, &cfg);
418 		if (ret < 0)
419 			goto ecfgrx;
420 
421 		host->bounce_buf = (u8 *)__get_free_page(GFP_KERNEL | GFP_DMA);
422 		if (!host->bounce_buf)
423 			goto ebouncebuf;
424 
425 		init_completion(&priv->dma_priv.dma_dataend);
426 		tasklet_init(&host->dma_issue,
427 			     renesas_sdhi_sys_dmac_issue_tasklet_fn,
428 			     (unsigned long)host);
429 	}
430 
431 	renesas_sdhi_sys_dmac_enable_dma(host, true);
432 
433 	return;
434 
435 ebouncebuf:
436 ecfgrx:
437 	dma_release_channel(host->chan_rx);
438 	host->chan_rx = NULL;
439 ereqrx:
440 ecfgtx:
441 	dma_release_channel(host->chan_tx);
442 	host->chan_tx = NULL;
443 }
444 
445 static void renesas_sdhi_sys_dmac_release_dma(struct tmio_mmc_host *host)
446 {
447 	if (host->chan_tx) {
448 		struct dma_chan *chan = host->chan_tx;
449 
450 		host->chan_tx = NULL;
451 		dma_release_channel(chan);
452 	}
453 	if (host->chan_rx) {
454 		struct dma_chan *chan = host->chan_rx;
455 
456 		host->chan_rx = NULL;
457 		dma_release_channel(chan);
458 	}
459 	if (host->bounce_buf) {
460 		free_pages((unsigned long)host->bounce_buf, 0);
461 		host->bounce_buf = NULL;
462 	}
463 }
464 
465 static const struct tmio_mmc_dma_ops renesas_sdhi_sys_dmac_dma_ops = {
466 	.start = renesas_sdhi_sys_dmac_start_dma,
467 	.enable = renesas_sdhi_sys_dmac_enable_dma,
468 	.request = renesas_sdhi_sys_dmac_request_dma,
469 	.release = renesas_sdhi_sys_dmac_release_dma,
470 	.abort = renesas_sdhi_sys_dmac_abort_dma,
471 	.dataend = renesas_sdhi_sys_dmac_dataend_dma,
472 };
473 
474 /*
475  * Whitelist of specific R-Car Gen3 SoC ES versions to use this DMAC
476  * implementation. Currently empty as all supported ES versions use
477  * the internal DMAC.
478  */
479 static const struct soc_device_attribute gen3_soc_whitelist[] = {
480         { /* sentinel */ }
481 };
482 
483 static int renesas_sdhi_sys_dmac_probe(struct platform_device *pdev)
484 {
485 	if (of_device_get_match_data(&pdev->dev) == &of_rcar_gen3_compatible &&
486 	    !soc_device_match(gen3_soc_whitelist))
487 		return -ENODEV;
488 
489 	return renesas_sdhi_probe(pdev, &renesas_sdhi_sys_dmac_dma_ops);
490 }
491 
492 static const struct dev_pm_ops renesas_sdhi_sys_dmac_dev_pm_ops = {
493 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
494 				pm_runtime_force_resume)
495 	SET_RUNTIME_PM_OPS(tmio_mmc_host_runtime_suspend,
496 			   tmio_mmc_host_runtime_resume,
497 			   NULL)
498 };
499 
500 static struct platform_driver renesas_sys_dmac_sdhi_driver = {
501 	.driver		= {
502 		.name	= "sh_mobile_sdhi",
503 		.pm	= &renesas_sdhi_sys_dmac_dev_pm_ops,
504 		.of_match_table = renesas_sdhi_sys_dmac_of_match,
505 	},
506 	.probe		= renesas_sdhi_sys_dmac_probe,
507 	.remove		= renesas_sdhi_remove,
508 };
509 
510 module_platform_driver(renesas_sys_dmac_sdhi_driver);
511 
512 MODULE_DESCRIPTION("Renesas SDHI driver");
513 MODULE_AUTHOR("Magnus Damm");
514 MODULE_LICENSE("GPL v2");
515 MODULE_ALIAS("platform:sh_mobile_sdhi");
516